Morphological and physiological characteristics for evaluation of salicylic acid effects on Celosia argentea L. under salinity stress

Salinity stress is one of the most important abiotic stresses in agriculture, from which about 20% of the total land cover is suffered. Considering the cultivation importance of C. argenea as well as the role of salicylic acid (SA) in tolerance and reducing the effects of salinity stress, the current study was conducted. This research was carried out as a factorial experiment based on a completely randomized design with three replications. The factors included salinity in four levels (0, 40, 80 and 120 mM NaCl) and SA at three levels (0, 1 and 2 mM). The results showed that the effects of salinity stress on morphological and physiological characteristics were significant, indicating a negative effect of salinity on growth and flowering of C. argentea. Foliar application of SA, especially at 1mM, improved the morphological and physiological characteristics. Correlation between the measured traits showed that proline, MDA and electrolyte leakage had a significant negative correlation with the other measured traits. As stress increased, stomatal conductance decreased, indicating closure of stomata during stress and plant resistance. In general, SA application (in particular with 1 mM concentration) increased photosynthesis rate through the improvement of plant pigments and proline contents under salinity stress. Therefore, due to its cheapness and compatibility with the environment, SA is a simple solution to reduce salinity stress in this plant.